The overall objective of the proposed research is the study of a bone resorptive glycoprotein and its relationship to osteolytic neoplastic disease and hypercalcemia. Particular emphasis will be placed on the complete chemical and physiochemical characterizaton of this protein which we have purified from human cancer ascites fluid. The proposed studies will include the elucidation of the complete amino acid and carbohydrae sequences of this Alpha2-glycoprotein. In addition, we will induce a specific antibody to the homogeneous bone resorptive protein which will permit the development of a radioimmuoassay for this globulin. The radioimmunoassay will be used to establish the identity or lack of identity of the ascites glycoprotein with other bone resorptive proteins such as osteoclast activating factor, to determine its cell origin and to evaluate the levels of the ascites protein in patients with osteolytic lesions of the skeleton and cancer related hypercalcemia.